US4534920A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing carbonizable oxidized fibers and carbon fibers
Assignee: Toray Industries Inc
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Filing: 1983-06-07
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Granted: 1985-08-13
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Expires: 2003-06-07
Abstract
Abstract Disclosed is a process for producing carbon fibers comprising providing cooling rollers in a 240 DEG to 400 DEG C. oxidative atmosphere, heating a precursor composed of continuous filaments in said oxidative atmosphere while intermittently and repeatedly bringing the precursor into contact with the cooling rollers to thereby convert the precursor to oxidized fibers and carbonizing the resulting oxidized fibers in an inert atmosphere of at least 800 DEG C.
Inventors
- 👤 Minoru Yoshinaga
- 👤 Nobuyuki Matsubara
- 👤 Ryuichi Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:35
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/20; D01F9/16; D01F9/21; D01F9/22; D01F9/32
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
84 words
A process for producing carbonizable oxidized fibers, which comprises oxidizing precursor fibers in an oxidizing atmosphere containing an oxidizing gas heated to about 240° to 400° C. by intermittently contacting and removing said precursor fibers on and from a cooling means positioned inside said oxidizing atmosphere, wherein the contact time per single contact of said precursor fibers with the cooling means is from about 0.1 to about 3 seconds, and the temperature drop caused by said contact is about 5° to about 30° C.
Claim 2
Dependent Claim
84 words
A process for producing carbonizable oxidized fibers, which comprises oxidizing precursor fibers in an oxidizing atmosphere containing an oxidizing gas heated to about 240° to 400° C. by intermittently contacting and removing said precursor fibers on and from a cooling means positioned inside said oxidizing atmosphere, wherein the contact time per single contact of said precursor fibers with the cooling means is from about 0.1 to about 3 seconds, and the temperature drop caused by said contact is about 5° to about 30° C.
Claim 3
Dependent Claim
24 words
The process for producing carbonizable oxidized fibers as recited in claim 1, wherein said cooling means is cooled with a refrigeration medium circulated therein.
Claim 4
Dependent Claim
19 words
The process for producing carbonizable oxidized fibers as recited in claim 1, wherein the cooling means is a roller.
Claim 5
Dependent Claim
19 words
The process for producing carbonizable oxidized fibers as recited in claim 1, wherein the cooling means is a plate.
Claim 6
Dependent Claim
19 words
The process for producing carbonizable oxidized fibers as recited in claim 1, wherein the cooling means is a pipe.
Claim 7
Dependent Claim
48 words
The process for producing carbonizable oxidized fibers are recited in claim 1, wherein the precursor fibers have previously been subjected to preliminary heat treatment prior to being oxidizing in the oxidative atmosphere to thereby reduce the amount of formed tarry product to about 5% by weight or less.
Claim 8
Dependent Claim
34 words
The process for producing carbonizable oxidized fibers as recited in claim 5, wherein the preliminary heat treatment of the precursor fibers is conducted by contacting them with heating rollers of 150° to 240° C.
Claim 9
Dependent Claim
35 words
The process for producing carbonizable oxidized fibers as recited in claim 1, wherein said precursor fibers are continuous fibers selected from the group consisting of acrylic fibers, polyvinyl alcohol fibers, pitch fibers, and cellulose fibers.
Claim 10
Dependent Claim
97 words
A process for producing carbon fibers, which comprises: (a) providing a cooling means positioned inside a 240° to 400° C. oxidative atmosphere, (b) heating a precursor composed of continuous filaments in said oxidative atmosphere to thereby convert the precursor to oxidized fibers, while intermittently and repeatedly bringing the precursor into contact with the cooling means, for a contact time of about 0.1 to about 3 seconds which causes a temperature drop in the precursor of about 5° to about 3° C., and (c) carbonizing the resulting oxidized fibers in an inert atmosphere of at least 800° C.
Claim 11
Dependent Claim
97 words
A process for producing carbon fibers, which comprises: (a) providing a cooling means positioned inside a 240° to 400° C. oxidative atmosphere, (b) heating a precursor composed of continuous filaments in said oxidative atmosphere to thereby convert the precursor to oxidized fibers, while intermittently and repeatedly bringing the precursor into contact with the cooling means, for a contact time of about 0.1 to about 3 seconds which causes a temperature drop in the precursor of about 5° to about 3° C., and (c) carbonizing the resulting oxidized fibers in an inert atmosphere of at least 800° C.
Claim 12
Dependent Claim
23 words
The process for producing carbon fibers as recited in claim 9, wherein said cooling means is cooled with a refrigeration medium circulated therein.
Claim 13
Dependent Claim
19 words
The process for producing carbonizable oxidized fibers as recited in claim 9, wherein the cooling means is a roller.
Claim 14
Dependent Claim
19 words
The process for producing carbonizable oxidized fibers as recited in claim 9, wherein the cooling means is a plate.
Claim 15
Dependent Claim
19 words
The process for producing carbonizable oxidized fibers as recited in claim 9, wherein the cooling body is a pipe.
Claim 16
Dependent Claim
43 words
The process for producing carbon fibers as recited in claim 9, wherein the precursor has previously been subjected to preliminary heat treatment prior to heating in the oxidative atmosphere to thereby reduce the amount of formed tarry product to about 5% or less.
Claim 17
Dependent Claim
36 words
The process for producing carbon fibers as recited in claim 14, wherein the preliminary heat treatment of the precursor is conducted by contacting it with heating rollers of 150° to 240° C. in an oxidative atmosphere.
Claim 18
Dependent Claim
33 words
The process for producing carbon fibers as recited in claim 4, wherein said precursor is continuous fibers selected from the group consisting of acrylic fibers, polyvinyl alcohol fibers, pitch fibers, and cellulose fibers.
Claim 19
Dependent Claim
38 words
The process for producing carbonizable oxidized fibers as recited in claim 1, wherein said cooling means are two pairs of cooling rollers, and said precursor fibers are wound at least ten times around each pair of cooling rollers.
Claim 20
Dependent Claim
37 words
The process for producing carbon fibers as recited in claim 9, wherein said cooling means are two pairs of cooling rollers, and said precursor fibers are wound at least ten times around each pair of cooling rollers.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-08-12 | 1989-02-11 | 1989-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-12 | 1993-02-11 | 1993-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-12 | 1997-02-11 | 1997-08-13 | $7700.00 | Window Closed / Lapsed |